Lewis o



Patented Mar. I4, |899.

No. s2|,249.

L. o. Hemel.

J A C K (Application med Dc. 12, 189s.)

(N0 Modal.)

lINrrnD STATES- PATENT y F FICE@ JACK.

SPECIFCATIO forming part of Letters Patent No. 621,249, dated March 14, 1899.

Application filed December 12,1898. Serial No. 699,050. (No model.)

' exact description of the invention, such as will enable others skilledy in the art to which it appertains to make and use the same.

This invention relates to lifting-jacks, and is particularly intended as an improvement upon the construction shown in Patent No. 536,594, dated April 2, 1895, the principal object of the present invention being to provide for a step-by-step lowering of the jack, which cannot be accomplished with the construction shown in said patent.

It is apparent that in the use of a lifting-4 jack it is often desirable to lower the load carried by it to a slight extent or a little at a time, and in evolving my invention with this end in view I have added certain features to a lifting-jack of the type shown in the patent above mentioned, whereby upon effecting a slight adjustment manipulation of the operating handle or lever will result in a lowering of the rack-bar tooth by tooth.

With the above-stated object in view the invention consists in certain novel features of construction and combinations of parts, the essential elements of which are recited in the appended claims, and a preferred form of embodiment of which is illustrated in the accompanying drawings, forming part of this specification.

Of said drawings, Figure 1 represents the lifting-jack in side elevation with the parts adjusted for the ordinary operation of lifting and the operating handle or lever elevated. Fig. 2 shows the upper portion of the liftingjack in section, the saine adjustment obtaining as in Fig. 1,'but the operating lever or handle being represented as depressed. Fig. 3 shows a sectionalized side elevation of the upper portion of the lifting-jack with the operating handle or leverelevated and the parts adj usted forstep-by-step lowering of the rackbar. Fig. 4 is a view similar to Fig. 3, the

operating lever or handle, however, being depressed and the relation of parts being correspondingly changed. Fig. 5 shows the parts The casing or hollow standard a, the rackbar b, the operating handle or lever c, and thelifting-pawld are all of much the same form of construction as shown in the patent hereinbefore mentioned, and the holding pawl or catch e is located and pivoted in substantially the samemanner, so as to gravitate into engagement with the teeth of the rack-bar. The operation of lifting is practically the same as with the construction shown in said patent, raising and lowering of the handle-lever c resulting in the pawl d successively engaging the teeth of the rack and the pawl e dropping behind the same as the rack-bar is pushed upwardly by the pawl d. The latter is provided with a pin d', as in the construction shown in the patent referred to, which pin projects through an opening of suitable size and shape in the side of the casing or hollow standard, and this pawl by means of said pin can b e withdrawn from engagement with the rack and brought to a position where upon upward movement it will engage a socket e', formed in the lower end of the upper pawl e, and will thereby cause the disengagement of the latter from the rack-bar, so as to leave the same free to drop to its lowest position, as described in the before-mentioned patent. As hereinbefore stated, however, it is often desirable to lower the rack-bar little by little, and for the accomplishment of this object I pivot to the upper pawl, between the arms thereof, as indicatedl at f, an arched swinging piece j", havingalongitudinal bifurcation fz. Projections in the form of' screws f3, entered in the vouter sides of the members of the bifurcated portion of said swinging piece constitute supports for the upper ends of a pair of spiral springs g, formed with eyes surrounding portions of said screws between the heads of the same and the sides of the swinging piece, and being also formed with similar eyes at their lower ends surrounding and suitably conned upon protruding portions of the pin d in the lower pawld. The said spiral springs are normally IOO closed, and .up-and-down movement of the lower pawl d oscillates the swinging piece on its pivot without aecting the upper pawl, as illustrated by Figs. l and 2, piece in its lowermost position abutting the pawl c, whereas when the operating-lever has been depressed there is a considerable space between said swinging piece and the outer or top surface e2 of the lower portion or crossbar of the said pawl.

A rotatable locking-piece or turn-button occupies the bifurcation of the swinging piece and is pivoted or swiveled to the pawl e, said turn-piece comprising a boss h, which bears against the surface e2 and through which a screw 7L passes, said screw entering a screwthreaded socket in the pawl e and constituting a bearing or pivot for the turn-button, which further comprises lateral projections i on opposite sides of the boss h, at the base of the same, said projections being triangular in end elevation and beveled on their upper sides, as shown at 17, to provide cam-surfaces rising from the outer lower corners of the projections and merging into the upper sloping sides of the latter, which result from the triangular formation thereof. Projectionsj on opposite sides of the boss h, at the upper end thereof, are formed with portionsj, confronting the projections t' and of similar formation thereto, being triangular in end elevation and their under surfaces being beveled, as shown at ji, so as to form cam-surfaces merging into the sloping surfaces which result from the triangular formation. Thumb-pieces `7'4 rise from the upper sides of the projections j to provide convenient means for manipulating the turn-button. Normally the latter will stand in the direction of the bifurcation of the swinging piece and will olTer no obstruction to oscillation of the same; but when said turn-button moves through a quarter of a circle it will be Seen that its lower projections z' are carried under the swinging piece, while itsv projections j are carried over the same and oscillation of the swinging piece on its pivot will be prevented. This quarter-turn of the button is made when it is desired to lower the rack-bar step by step. Vith the parts in the position shown in Fig. l such manipulation of the turn-button will cause two of the canrsurfaces z" on the lower projectionsi to operate against the under sides of the members of the bifurcated portion of the swinging piece, so as to force the latter away from the surface e2, as illustrated in Fig. 3, and this movement of the swinging piece will disengage the lower pawl d from the rack-bar through the medium of the spiral springs, which, it willbe seen, constitute links of a toggle of which the lower pawl is a member, said toggle being partially straightened by the above-described operation and this straightening necessarily resulting in disengagement of the pawl from the rack and, moreover, resulting in the springs being put the swinging under tension. This adjustment of parts having been effected, depression of the operating-lever first has the effect of moving the end of the lower pawl past the shoulder of the tooth it has previously engaged and behind the tooth next above, the closing of the springs allowing this movement of the pawl to take place without aifecting the upper pawl and the toggle form of connection insuring the movement of the lower pawl towald the rack-bar. Further upward movement of the pawl d, produced by depression of 'the operating-lever, will cause the disengagement of the upper pawl from the rack, as shown in Fig. 4, outward movement of the swinging piece being prevented by the upper projections] of the turn-button and outward movement of the pawl necessarily ensuing through the medium of the springs, which now constitute links connecting the lower pawl with the upper pawl. A lowering of the rack-bar the extent of one tooth is the necessary result of the above-described operation. Should the turn-button be manipulated when the parts are in the position shown in Fig. 2, the camsurfacesj2 of the upper projections by operating against the uppersides of the bi-furcated portion of the swinging piece will effect the disengagement of the upper pawl from the rack, so that upon raising the operating handle or lever the rack-bar will be lowered to the extent of one toot-h, the consequent low.

ering of the pawl d being necessarily accompanied by movement of the upper pawl into position for engagement with the rack.

It will be seen that a construction such as above described is well calculated to fulfil the object primarily stated. However, itis to be understood that the invention is capable of embodiment in other forms than that here shown, and therefore in the claims which follow essential elements of the invention are recited without restriction to details of construction.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is-

l. In a jack, the combination of a standard, a rack-bar slidingly fitted to the same, a lever pivoted to the standard and carrying an upstanding pivotal pawl adapted to engage the rack-bar, an upper pendent pawl pivoted to the standard and adapted to engage the rack, and a link connection between the two pawls whereby rockin g of the lever alt ernatel y engages them with the rack-bar to permit step-by-step lowering of the same.

2. In ajaek, the combination of a standard, a rack-bar slidin gl y itted to the same, a lever pivoted to the standard and carrying an upstanding pivotal pawl adapted to engage the rack-bar, an upper pendent pawl pivoted to the standard and adapted to engage the rack, and a link connection between the two pawls together with a lock whereby the link connection can bemade effective to produce al- IOO IIO

ternate engagement of the pawls with the rack-bar under rocking of the lever, substantially as and for the purposedescribed.

3. In a jack, the combination of a standard, a rack-bar slidingly fitted to the same, a lever pivoted to the standard and carrying an upstanding pivotal pawl adapted to engage the rack-bar, an upper pendent pawl pivoted to the standard and adapted to engage the rack, a swinging piece on said upper pawl, a link connecting said swinging piece with the lower pawl, and a locking-piece for said swinging piece manipulative to lock the latter to the upper pawl whereby rocking of the lever may produce alternate engagement of the pawls with the rack-bar, substantially as and for the purpose described.

Il. In a jack7 the combination of a standard, a rack-bar slidingly litted to the same, a lever pivoted to the standard and carrying an upstanding pivotal pawl adapted to engage the rack-bar, an upper pendent pawl pivoted to the standard and adapted to engage the rack, a swinging piece on said upper pawl, a link connecting said swinging piece with the lower pawl, and a locking-piece for said swinging piece manipulative to lock the latter to the upper pawl whereby rocking of the lever may produce alternate engagement of the pawls with the rack-bar, said locking-piece having a portion which acts against the swinging piece to initially disen gage one pawl from' the rack.

5. In ajack, the combination of a standard, a rackbar slidingly fitted to the same, alever pivoted to the standard and carrying an upstanding pivotal pawl adapted to engage the rack-bar, an upper pendent pawl pivoted to the standard and adapted to engage the rack, a swinging piece on said upper pawl, a link connecting said swin ging piece with the lower pawl, and a locking-piece having a double cam formation for engagement with opposite sides of the swinging pieceto disengage either pawl from the rack-bar in locking the swinging piece to the upper pawl, substantially as and for the purpose described.

6. In a jack, the combination of a standard,

a rack-bar. slidingly fitted to the same, a lever pivoted to the standard and carrying an upstanding pivotal pawl adapted to engage the rack-bar, an upper pendent pawl pivoted to the standard and adapted to engage the rack, a swinging piece on said upper pawl, a link connecting said swinging piece with the lower pawl, and a locking turn-piece having a double cam formation for engagement with opposite sides of the swinging piece to disengage either pawl from the rack in locking the swinging piece to the upper pawl, substantially as and for the purpose described.

'7. In a jack, the combination of astandard, a rack-bar slidingly litted to the same, a lever pivoted to the standard and carrying an upstanding pivotal pawl adapted to engage the rack-bar, an upper pendent pawl pivoted to the standard and adapted to engage the rack,

a swinging piece of bifurcated form on said upper pawl, links connecting said swinging piece with the'lower pawl, and a turn-piece swiveled to the upper pawl and occupying the `bifurcation of the swinging piece, said turnpiece having confronting beveled shoulders or inclined faces on each side for engagement with opposite sides of the swinging piece to lock the same to the pawl and to initially disengage one of the pawls from the rack-bar, substantially as and for the purposedescribed.

8. In a jack, the combination of a standard, a rack-bar slidingly fitted to the same, a lever pivoted to the standard and carrying an upstanding pivotal vpawl adapted to engage the rack-bar, an upper pendent pawl pivoted to the standard and adapted to engage the rack, a swinging piece normally seating downwardly against an upper surface or shoulder of the upper pawl, a spring connecting said swinging piece with the lower pawl and forming a toggle therewith, and means for moving the swinging piece away from the shoulder against w-hich it normally lies and thereby straightening the said toggle, together with means for locking the swinging piece against further outward movement relative to the upper pawl, substantially as and for the purpose described.

9. In a jack, the combination of a standard, a rack-bar slidingly fitted to the same, a lever pivoted to the standard and carrying an upstanding pivotal pawl adapted to engage the rack-bar, an upper pendent-pawl pivoted to the standard and adapted to engage the rack, and a link connection between the two pawls in the form of a spring whereby rocking of the lever alternately engages them with the rack-bar to permit step-by-step lowering of the same.

l0. In a jack, the combination of a standard, a rack-bar slidingly fitted to the same, a lever pivoted to the standard and carrying an up- ICO IIO

standing pivotal pawl adapted to engage the rack-bar, an upper pendent pawl pivoted to the standard and adapted to engage the rack, a swinging piece on said upper pawl, a link in the form of a spring connecting said swinging piece with the lower pawl, and alockingpiece for said swinging piece manipulative to lock the latter to the upper pawl whereby rocking of the lever may produce alternate engagement of the pawls with the rack-bar, substantially as and for the purpose described.

ll. In a jack, the combination of a standard, a rack-bar slidingly fitted to the same, a lever pivoted to the standard and carrying an upstanding pivotal pawl adapted to engage the rack-bar, an upper pendent pawl pivoted to the standard and adapted to engage the rack, a swinging piece of bifurcated form on said upper pawl, links in the form of springs connecting said swinging piece with the lower pawl, and a turn-piece swiveled to the upper pawl and occupying the bifurcation of the swinging piece, said turn-piece having oonln testimony whereof I affix my signature fronting beveled shoulders orvinclined faces in presence of two witnesses. on each side for engagement with opposite LEWIS O HENGGI sides of the swinging piece to look the same 5 to the pawl and to initially disengage one of Witnesses:

the pawls from the rack-bar, substantially as F. W. BEALAFELD, and for lhe purpose described. ARCH H. ROUMED. 

